Air heater and exhaust gas diluting apparatus for incinerator

ABSTRACT

An air heater and exhaust gas diluting apparatus for incinerator in which one or more of the outer walls of the incinerator are formed with spaced wall plates with baffle plates positioned to form a tortuous air passage between the spaced wall plates, duct means connected between the tortuous air passage and the exhaust gas chamber of said incinerator and fan means associated with the duct to draw air through the tortuous passage to heat the same and discharge the same into the exhaust gas chamber to add heat thereto and dilute the exhaust gases therein.

United States Patent Bowman 1 July 25,1972

[54] AIR HEATER AND EXHAUST GAS DILUTING APPARATUS FOR INCINERATOR [72] lnventor:

[73] Assignee: Bowman Enterprises, Inc., Baltimore, Md.

[22] Filed: Sept. 25, 1970 21 Appl. No.: 75,419

Vernon 1). Bowman, Kettering, Ohio 3,215,101 11/1965 Hoskinson ..1lO/8A Primary Examiner-Kenneth W. Sprague Attorney-J. Wesley Everett and George L. Brehm 5 7] ABSTRACT An air heater and exhaust gas diluting apparatus for incinerator in which one or more of the outer walls of the incinerator are formed with spaced wall plates with baffle plates positioned to form a tortuous air passage between the spaced wall plates, duct means connected between the tortuous air passage and the exhaust gas chamber of said incinerator and fan means associated with the duct to draw air through the tortuous passage to heat the same and discharge the same into the exhaust gas chamber to add heat thereto and dilute the exhaust gases therein.

3 Claims, 4 Drawing Figures Patentod July 25, 1972 BEST AVAEABLE copy 3,678,869

2 Sheets-Sheet l F I G. 2 2e 27 4 l6 l0 l2 l5 VERNON 0. BOWMAN INVENTOR l9 Patented Jul 25, 1972 EST AVAILABLE COPY 3.

v -2 Sheets-Sheet 2 imm- I k l 36 VERNON D. BOWMAN M 7 IM'ENTOR B ATTORNEY AIR HEATER AND EXHAUST GAS DILUTING APPARATUS FOR INCINERATOR This invention relates to air heater and exhaust gas diluting device for incinerator and is concerned more specifically with a device for heating air to be used in connection with an incinerator equipped with an exhaust gas purifier and scrubber device. Such apparatus functions more effectively when hot air in great quantities is introduced, not only to aid in the complete combustion of the bumable components of the gases passing therethrough but also to greatly dilute such gases before they are expelled into the atmosphere. The instant device has been found to efficiently provide a very generous supply of hot air for the purpose stated.

The present invention utilizes the heat generated by the combustion of the material in the incinerator itself and thereby greatly increases the efficiency of the apparatus and reduces the cost of operation.

It is an object of the present invention to provide a device of the character above generally set out which is simple in structure and efficient in operation.

It is another object to provide such a device which can be incorporated in an incinerator and air purifying apparatus with a minimum of change in the basic design of the same.

These and other objects and advantages of the device will become more apparent as this description proceeds, reference being had to the accompanying drawings forming a part of this specification, and in which:

FIG. 1 is a perspective view of an incinerator incorporating one form of air heater and exhaust gas diluter according to my invention;

FIG. 2 is a sectional view of the jet type fan means used in the device shown in FIG. 1;

HO. 3 is a fragmentary view of a modified form of heater with portions removed to show the interior construction thereof; and

FIG. 4 is a fragmentary view of the complete heater-diluter device utilizing the modified form of heater shown in FIG. 3.

Referring now more specifically to the drawing and, for the present, to FIGS. 1 and 2 thereof, generally indicates an incinerator which is of conventional cabinet design with access doors 11 and 12 for loading and unloading and an exhaust gas discharge stack of the like 13. The incinerator with its appurtenances mentioned is quite well known and, of itself, forms no novel part of the present invention.

Each side wall of the incinerator cabinet is provided with a double walled heater member 14 formed by spaced plates 15 and 16. Bafile members 17 and 18 are positioned between the plates, and, as may be seen by inspection of FIG. 1, these baffles are of such length and are so spaced and located between the side plates as to forma passage between the plates which is tortuous or roughly zig-zag in shape. The space between the plates is closed at the bottom and rear by narrow plates 19 and 20 respectively. The front is closed above the baffle 17 by plate 21, leaving an opening 22 below the baffle, and the top is closed by plate 23 which extends from the front plate 21 toward the rear, at which point an outlet duct 24 is formed. It is evident that air entering the opening 22 can follow a back and forth path between the plates and around the baffles and exit through the duct 24, and if the inner plate 15 is hot as it will be from the burning contents within the incinerator, the air in its passage through the space between the plates will be likewise heated.

To propel air through the heater a fan means generally indicated by reference numeral 25 is provided. This fan means is shown in section in FIG. 2 and comprises an outer shell with a large cylindrical section 26 at one end, a small cylindrical section 27 at the other end and an intermediate frusto-conical section 28 connecting the two cylindrical end sections. An inner frusto-conical member 29 is fixed within the outer shell with its large end located at an intermediate point along the length of the large cylindrical section 26 and is of a size to tightly fit the internal diameter of the large cylindrical section while its smaller end extends approximately to the point where the frusto-conical section 28 and the smaller cylindrical section are joined, and is of a diameter considerably smaller than the diameter of the smaller cylindrical section.

A power driven fan 30 is located within the large cylindrical section adjacent the large end of the inner frusto-conical member 29 and an adjustable air valve or damper 31 of any conventional type is provided adjacent the end of the large cylindrical section whereby the amount of air entering this end may be regulated.

The fan means is connected between the heater and the exhaust gas discharge stack 13 as shown in FIG. 1. The smaller cylindrical section 27 forms the discharge tube of the fan means and is positioned to blow into the stack 13 through an opening 32 in the latter. The outlet duct 24 from the heater is connected through a duct 33 with the fan housing in the frusto-conical section 28 thereof at a point somewhat behind the end of the inner conical member 28 whereby a stream of air passing through the inner conical member will create a suction on the space behind the end of the inner conical member or in other words will function as an aspirator and thus draw air through the heater, through the duct 33 and into the fan housing and therein be picked up in the air stream through the device and out the section 27 and into the stack 13.

A branch duct 34 leading from the duct 33 is connected to the housing of the fan means ahead of the fan 30 and between the same and the damper 31. It can be seen that as the damper is progressively closed, more and more air will be drawn through the duct 34 whereas as the damper is opened less air will be drawn through the duct 34 and more air drawn directly through the end of the section 26 and the damper and through the fan. It is evident that this arrangement affords a means for regulating the temperature of the discharge air from the fan means into the stack 13, for when the damper is closed all the air discharged from the fan means will be air from ducts 33 and 34 which has passed through the heater, whereas when the damper is open, a large portion of the air discharged will be room temperature air drawn in through the open end of section 26 of the fan means mixed with heated air drawn in through ducts 33 and 34.

It is obvious that if two heaters are provided as is shown in FIG. 1 the elements thereof and of the duct means from the heaters to the fan means must be duplicated.

The modified form shown in FIGS. 3 and 4 is similar to that of FIG. 1. ln thisform the heater is located on the top of the incinerator cabinet and is similar in basic design to the heater of the above described embodiment and has top and bottom walls 35 and 36, front and rear walls 37 and 38 and end walls 39 and 40. Bafile plates 41, 42, 43 and 44 are positioned within the heater enclosure in such a manner as to provide a back and forth path from each end of the heater enclosure toward the center thereof as indicated by the directional arrows shown in FIG. 3. The end portions of the rear wall 38 are omitted between bafile plates 41 and 44 and the end walls 39 and 40 to provide air inlets to the heater, while a centrally located duct 45 from the top of the heater forms the air outlet therefrom.

The duct 45 is connected to the fan means housing in the manner of the duct 33 in the first modification described and a branch duct 46 from the duct 45 is connected to the fan means housing between the fan and the damper means in the same manner as the branch duct 34 in the first form described.

The fan means in the modified form is the same as in the first form and its outlet is connected to the exhaust stack of the incinerator in the same manner as in the first form and the two forms function in the same manner.

It is to be understood that the exhaust stack from the incinerator may include an exhaust gas cleaning and scrubbing apparatus as shown in my co-pending applications Ser. No. 773,741 and Ser. No. 790,299, in which event the source of controlled temperature heated air afiorded by the instant device will be of benefit not only in greatly diluting the exhaust gases emitted into the atmosphere but will assist in consuming combustible materials in the exhaust gases as they are treated in the cleaning and scrubbing device.

I claim:

l. in combination with an incinerator having a housing forming a chamber for burning combustible material therein and an exhaustduet connected with said housing for conducting the mailer: of combustion from the housing, an air heater associated with said housing, said heater receiving its heat from the burning material in said housing, said air heater comprising an enclosure having an air inlet port for receiving fresh air and an air outlet port connected to the exhaust duct, an air propelling means connected between the air heater and the exhaust duct, said heater having a plurality of baffle plates positioned in saidenclosure defining a tortuous path for the air passing through the said heater, the heater being positioned adjacht the chamber for receiving heat therefrom.

2. The structure as defined in claim 1 wherein said air propelling means comprises an enclosure having an air inlet and an air outlet end, the latter end being connected to the incinerator exhaust duct, a tapered air jet tube positioned adjacent the inlet end of the enclosure and extending therethrough for a predetermined distance toward the outlet end of the enclosure, a fan positioned in the inlet end of the enclosure for forcing air from said air inlet through said air jet tube to the outlet end of the said enclosure into the incinerator exhaust duct, at least one air conduit leading from said air heater to the said enclosure in the area of the jet tube whereby the heated air will be drawn into the enclosure by aspirator action and discharged into the incinerator exhaust duct.

3. The structure defined in claim 2 wherein a damper valve is positioned in the enclosure of said air propelling means adjacent the inlet end thereof and in front of the said fan for regulating the intake of atmospheric air, an air conduit having one end connected to the heater and its opposite end connected to the enclosure on the side of the fan opposite the jet tube.

t i i l= 

1. In combination with an incinerator having a housing forming a chamber for burning combustible material therein and an exhaust duct connected with said housing for conducting the products of combustion from the housing, an air heater associated with said housing, said heater receiving its heat from the burning material in said housing, said air heater comprising an enclosure having an air inlet port for receiving fresh air and an air outlet port connected to the exhaust duct, an air propelling means connected between the air heater and the exhaust duct, said heater having a plurality of baffle plates positioned in said enclosure defining a tortuous path for the air passing through the said heater, the heater being positioned adjacent the chamber for receiving heat therefrom.
 2. The structure as defined in claim 1 wherein said air propelling means comprises an enclosure having an air inlet and an air outlet end, the latter end being connected to the incinerator exhaust duct, a tapered air jet tube positioned adjacent the inlet end of the enclosure and extending therethrough for a predetermined distance toward the outlet end of the enclosure, a fan positioned in the inlet end of the enclosure for forcing air from said air inlet through said air jet tube to the outlet end of the said enclosure into the incinerator exhaust duct, at least one air conduit leading from said air heater to the said enclosure in the area of the jet tube whereby the heated air will be drawn into the enclosure by aspirator action and discharged into the incinerator exhaust duct.
 3. The structure defined in claim 2 wherein a damper valve is positioned in the enclosure of said air propelling means adjacent the inlet end thereof and in front of the said fan for regulating the intake of atmospheric air, an air conduit having one end connected to the heater and its opposite end connected to the enclosure on the side of the fan opposite the jet tube. 